Tilt back swivel chair



Patented `ian. 25, 1944 S PAT Y rtree easily attained materials such as wood, without `the.necessity of employing numerous castings,

fittings, machined parts and the like. Tilt back chairs, particularly for oice use, have been manufactured for agreatmany:years'A and are characterized by the use of a pedestal or base cbupled to a seat generally provided 'with a back and arms, whereby the seat may be pivoted about a'vertical axis and simultaneously, under thev 'control'of the occupant of the chair, said seat'm'ay be tilted about a horizontal Aaxis, extending from` side to side of the occupant. Chairs f this character have ordinarily employed a number of metal parts "including springs and fittings 'whichlconnected the seat to the pedestal and'permitt'ed the tiltingmotion totake place.

Tilt back chairs of the character described have been found conducive to increased efficiency of oiice workers, the tilting motion permitting a certain amount of relaxation and exercise without causing the occupant to leave his desk However, such chairs require metal parts which need be cast, machined and otherwise finished and the shortage of metal and skilled metal workers has substantially curtailed the manufacture of tilt back chairs.

The present invention is directed to a tilt back chair capable of pivoting about a vertical axis, the chair construction of the present invention virtually eliminating the use of metal.

Generally stated, the construction of the present invention contemplates the use of a platform pivotally connected to the pedestal or base, said platform interlocking with downwardly extending retaining members carried by the bottom of the seat, the platform and retainers being pivotally connected about a horizontal axis, the elements being so arranged that a limited tilting motion may be imparted to the chair seat. Since the platform, retainers and even the horizontally disposed hinge pins may be made of wood or other non-stragetic material, a great saving in metal and the time of skilled metal workers is attained.

An object of the present invention, therefore, is to disclose and provide a tilt back chair of improved simple construction.

A further object o-f the invention is to disclose and provide an effective tilt back chair in which metal parts have beenrvirtually eliminated.

l f frnese 'and other objects of theinvenuon win become" abparent'tq these skiued in' the artfim the ffollowing detailed description v*of lthe invention, reference being had to the appended drawing for :the purpose of facilitating understandlng. Y s In metering:

, 4ig. l is a side elevati n of one form of chair ,embraced bythe present invention. big. 2 isan enlargedtransverse section taken alongthe plane lI-II of Fig.11. N Fig-3 isa horizontal section taken along the plane 111-111. l

Asshown in the drawing, the chair may include the usual elements, such as a pedestal, gener-ally indicated atl Lembracing the centrallyrdisposed Dier 2 and radially and'downwardly` extending legs 3,-4 and-the like, such legs'beingordinarily providedwith casters as indicated at 5. Positioned above the-pedestal is the vseat-l provided with la backand arm rests 8. v-

, '1; `rpair'of spaced-downwardly extending retainerelements is attached to the bottom of the rseat; such elements vbeing indicated at AI 6 and IiI These elements extend from front to rear of the seat I5 and are preferably spaced a distance not less than one-half the total width of the seat.

A platform, generally indicated at I2, is provided, said platform having a pair of spaced upwardly extending members I3 and IZB adapted to nest within the downwardly extending retainers IU and II. These upwardly extending members I3 and I4 preferably have a length in excess of 0.5 or 0.6 of the depth of the seat. The upper edges of the members I3 and Il are substantially flat or horizontal in their front po-rtions, the rear portion of the upper edges of said members beine rearwardly and downwardly inclined.

The front or substantially horizontal upper edge is indicated at I5 whereas the rearwardly and downwardly inclined edge is indicated at I5. The flat or horizontal edge portions I5 are adapted to rest against the bottom of the seat 6 and the length of these flat horizontal edges I5 is less than the length of the inclined edges it.

Means are provided for attaching the platform I2 to the pedestal for pivotal movement about a vertical axis. Such means may include a boss Il carried by the platform, the lower surface of the boss being provided with an annular ring i8 having a downwardly extending bead or annular protuberance. The ring I3 is preferably of metal or some relatively hard, smooth material. Opposing this ring is the top of the pier 2 which is also provided with an annular ring I9 having an upwardly extending bead or protuberance adapted to contact with the ring I8. An axial bore is formed through the boss l1 and the pier 2 of the pedestal and the platform I2 is connected to the pedestal as by means of a bolt 20 and lock nuts 2I. Pivotal movement of the platform on the pedestal is thus permitted.

Horizontally extending pivot pins 23 and 24 connect the retainers ID and II with the correspending upwardly extending members I3 vand I4. Instead of separate pins 23 and 24, a single long pivot pin may be used. The axis of the pivot CTI pins 23 and 24 preferably lies forwardly of the Y vertical axis of pivotal movement between'the-u platform and the pedestal as best illustrated in Fig. 1, since it has been found that when the pivot axis is so disposed substantially no load is carried by the pivot pins, substantially all of the weight being supported directly by the upper edges of members I3 and I4. Two or more compression springs are carried by the rear ofthe platform I2 and between the platform andthe bottom of the seat 6. Said springs are indicated at 25 and 26 and normally cause the bottom ofthe seat B to be in contact with the flats I5 of the upwardly extending members I3 and I4. The occupant, however, may lean against the,l back 'I and overcome the springs 25 and 26, thereby causing the seat 6to tilt about the pivot pins 23 and 24 so as to cause the/bottom of the seat 6 to contactv the inclined portions I6 Vof the members I3 and I4. It is to be understood that instead of springs 25 and 26, compressible elements made of plastic, rubber composition or the like may be substituted.

1n order to permit vertical adjustment, the pier 2 may be made of more than one piece and provision made for the insertion or removal of certain shims or portions thereof so as to raise or lower the level at which the two opposing rings I8 and I9 are placed. The pier 2, for example, may bemade of the elements 2 and 2f pinned together as by means of a pin 21. An .additional annular ring of material could then beinserted between the elements 2 and 2', such element being provided with a suitable perforation to receive the pin 21, thereby increasing the height of the chair.

It will be evident 'from the description given hereinabove that a chair of simple construction has been provided, the chair being capable of pivotal movement about a vertical axis and tilting about a horizontal axis without the necessity of employing complex arrangements of springs, castings and other metal parts requiring careful workmanship. All changes and modications coming within the scope of the appended claim are embraced thereby.

I claim:

`In a tilt back swivel chair including a seat and a pedestal, the combination of: a pair of spaced downwardly extending retainer elements attached tothe bottom of the seat and extending from front to rear thereof; a platform provided with a ,pair of spaced upwardly extending members adapted to nest within said retainers, said members having a length not less than 0.6 of the depth of the seat, the upper edge of each of said members being fiat in front and downwardly and rearwardly inclined in back, the length of said inclined upper edges being greater than the length of the front portion of said upper edges; means for attaching said platform to the pedestal for pivotal movement thereon about a vertical axis, said means including a pair of opposed annular rings provided with opposing protruding beads adapted to slidably contact each other, one` of the rings being connected to the -pedestal and another to the platform; horizontally extending pivot pins connecting saidV retainer elements and upwardly extending members, said pivot pins lying forwardly of the vertical axis of pivotal movement between platform and pedestal; and spring means carried by the rear of the platform and between the platform and bottom of the seat.

HERMAN SCHLORMAN. 

